The historic climate change report by the UN-backed Intergovernmental Panel on Climate Change (IPCC), released on Monday has been termed as ‘code red’ for humanity.
The report has given some beyond-stark revelations.
Warming does not distinguish regions
“Climate change is not a problem of the future, it’s here and now and affecting every region in the world,” said Dr Friederike Otto from the University of Oxford, and one of the many authors on the UN’s IPCC report.
For those who live in the West, the dangers of warming our planet are no longer something distant, impacting people in faraway places.
The 1.5C threshold
A special report on 1.5C in 2018 showed the advantages of staying under the 1.5C limit were massive compared to a 2C world. Getting there would require carbon emissions to be cut in half, essentially, by 2030 and net zero emissions reached by 2050. Otherwise, the limit would be reached between 2030 and 2052.
The new IPCC report states that under all scenarios, the threshold is reached by 2040. If emissions aren’t reined in, 1.5C could be gone in around a decade.
“The 1.5C threshold is an important threshold politically, of course, but from a climatic point of view, it is not a cliff edge – that once we go over 1.5C, suddenly everything will become very catastrophic,” explained Dr Amanda Maycock, from the University of Leeds, and one of the authors of the new report.
“The very lowest emissions scenario that we assess in this report shows that the warming level does stabilise around or below 1.5C later on in the century. If that were the pathway that we would follow, then the the impacts would be significantly avoided.”
No stopping for rising sea levels
A lack of clear research saw previous IPCC reports exclude the potential drastic impacts of the melting of the Greenland and Antarctic ice sheets.
However this time, the report shows that under current scenarios, the seas could rise above the likely range, going up to 2m by the end of this century and up to 5m by 2150. While these are unlikely figures, they can’t be ruled out under a very high greenhouse gas emissions scenario.
That’s bad enough – but even if we get a handle on emissions and keep temperatures around 1.5C by 2100, the waters will continue to rise long into the future.
“With gradual sea-level rise, those extreme sea-level events that have occurred in the past, just once per century, will occur more and more frequently in the future,” said Valérie Masson-Delmotte, co-chair of the IPCC working group.
A thread of hope
Now that the warnings are clearer and more dire – scientists want to make sure they are certain about how to tackle the crisis.
Scientists use a phrase – equilibrium climate sensitivity – to capture the range of warming that could occur if CO2 levels were doubled.
“We are now able to constrain that with a good degree of certainty and then we employ that to really make far more accurate predictions,” said Prof Piers Forster from the University of Leeds, and an author on the report.
“So, that way, we know that net zero will really deliver.”
Nervous politicians, busy courts
The IPCC report comes just a couple of months before the critical COP26 climate conference in Glasgow, meaning the table will be overful of negotiations. The IPCC has some form here: their previous assessment in 2013 and 2014 paved the way for the Paris climate agreement.
This new study is far clearer and more confident about what will happen if politicians don’t act.
If they don’t act promptly and COP26 ends in an unsatisfactory fudge, then the courts might become more involved.
“We’re not going to let this report be shelved by further inaction. Instead, we’ll be taking it with us to the courts,” said Kaisa Kosonen, senior political adviser at Greenpeace Nordic.